I would not buy this if I could not see it working.
You could fix the graticule.
But anything else is almost impossible to service on Japanese Scopes, although they are very good machines, there is no chance to get any Service Manuals on any Japanese Scope that I am aware of.The Scope Tube is a traditional tube, not just a Monitor like we see on some old digital scopes. If it is damaged, scope is not worth anything.Looking at the pictures, it reminds me of my HP 1980 (Introduced in 1985) Scope, a kinda cross between an Analog and Digital, with very unusual parts that cannot be found.
By the way the Sigilent recommended is in Luxembourg. but it does sound like a decent deal.